Analysis: This question is mainly about understanding half the meaning. Remove half, leaving 10 meter, indicating that this rope has two 10 meters.

The formula is:

1, 10+ 10=20 (m)

2 10×2 = 20 (m)

Extended data:

The knowledge of "doubling" not only implies the idea of set, but also is the early stage of understanding the concept of "doubling" and the significance of multiplication in the future.

The concept of "half" is the embodiment of the idea of "half division" and the concept of "equal division" in division.

Solutions to application problems:

1, analysis method: analysis method is a thinking method that starts from the problem sought in the problem and gradually finds out the known conditions necessary to solve the problem.

2. Decomposition method: A complex application problem is decomposed into several basic application problems, from which clues to solve the problem can be found.

3. Hypothesis method: Hypothesis method is to make appropriate assumptions about some phenomena or relationships in the topic when solving problems, and then use the contradiction between facts and assumptions to find the correct solution.